fix(memcheck): include free swap space in memory check (#1209)

closes #1185
- add swapfree to available to get estimated memory availability

Author: acburdine

lib/commands/doctor/checks/check-memory.js

@@ -1,19 +1,16 @@
-'use strict';
 const sysinfo = require('systeminformation');
-const SystemError = require('../../../errors').SystemError;
+const {SystemError} = require('../../../errors');
 
 const MB_IN_BYTES = 1048576;
 const MIN_MEMORY = 150;
 
-function checkMemory() {
-    return sysinfo.mem().then((memoryInfo) => {
-        const availableMemory = memoryInfo.available / MB_IN_BYTES;
+async function checkMemory() {
+    const {available, swapfree} = await sysinfo.mem();
+    const availableMemory = (available + swapfree) / MB_IN_BYTES;
 
-        if (availableMemory < MIN_MEMORY) {
-            return Promise.reject(new SystemError(`You are recommended to have at least ${MIN_MEMORY} MB of memory available for smooth operation. It looks like you have ~${parseInt(availableMemory)} MB available.`));
-        }
-        return Promise.resolve();
-    });
+    if (availableMemory < MIN_MEMORY) {
+        throw new SystemError(`You are recommended to have at least ${MIN_MEMORY} MB of memory available for smooth operation. It looks like you have ~${availableMemory} MB available.`);
+    }
 }
 
 module.exports = {

test/unit/commands/doctor/checks/check-memory-spec.js

@@ -1,4 +1,3 @@
-'use strict';
 const expect = require('chai').expect;
 const sinon = require('sinon');
 
@@ -44,7 +43,7 @@ describe('Unit: Doctor Checks > Memory', function () {
     });
 
     it('fails if not enough memory is available', function () {
-        const memStub = sinon.stub(sysinfo, 'mem').resolves({available: 10});
+        const memStub = sinon.stub(sysinfo, 'mem').resolves({available: 10, swapfree: 0});
         const memCheck = require(modulePath);
 
         return memCheck.task().catch((error) => {
@@ -55,7 +54,16 @@ describe('Unit: Doctor Checks > Memory', function () {
     });
 
     it('passes if there is enough memory', function () {
-        const memStub = sinon.stub(sysinfo, 'mem').resolves({available: 157286400});
+        const memStub = sinon.stub(sysinfo, 'mem').resolves({available: 157286400, swapfree: 0});
+        const memCheck = require(modulePath);
+
+        return memCheck.task().then(() => {
+            expect(memStub.calledOnce).to.be.true;
+        });
+    });
+
+    it('passes if there is enough memory (using swap space)', function () {
+        const memStub = sinon.stub(sysinfo, 'mem').resolves({available: 10, swapfree: 157286400});
         const memCheck = require(modulePath);
 
         return memCheck.task().then(() => {